Quaternization of guar gum with in situ generated hydroxyprpopyl dimethylbenzyl ammonium chloride from N,N-dimethylbenzylamine and epichlorohydrin for the effective removal of anionic dyes from simulated wastewater
Kavita Chauhan, Sandeep Chauhan, Kiran Kumar, Ghanshyam S. Chauhan
Abstract
We report a quaternized guar gum (QGG) by grafting hydroxypropyl dimethylbenzyl ammonium chloride (HPDMBAC) onto guar gum (GG). HPDMBAC was obtained in situ from N , N -dimethylbenzyl amine and epichlorohydrin . The as-synthesized QGG was characterized by FTIR, XRD , FESEM, BET, EDS , zeta potential , and surface charge analysis. The QGG is a rapid and efficient adsorbent for the anionic dyes, Congo red (CR) and methyl orange (MO), from simulated wastewater with respective %removal of 96.16 % for CR in 25 min and 98.02 % for MO in 30 min. The adsorption followed pseudo-second order kinetics with the highest value of correlation coefficient and the lowest values of error function (χ 2 ), root mean square error (RMSE) and normalized standard deviation (Δq%) for both the dyes. The Langmuir isotherm showed the better fitting of adsorption data with high maximum adsorption capacity of 213.30 and 305.44 mgg −1 for CR and MO, respectively. Additionally, the small value of χ 2 , RMSE and Δq% for Langmuir isotherm revealed its best fitting for both the dyes. Furthermore, the QGG demonstrated significant reusability for both the dyes studied for 15th adsorption-desorption cycles. Thus, QGG has a palpable potential as a cost-effective and sustainable adsorbent for removal of anionic dyes from wastewater.